Larry Davis, the notorious Bronx killer who was stabbed to death in prison last week, was effectively cut off from the outside world when he was sentenced for murder in 1991. But during his years of incarceration, he found a way to reach beyond his prison bars.

It would happen during the deep of night, while most people were asleep. Off and on for more than a decade, Mr. Davis’s words — intense, driven, sometimes angry — were broadcast by the leftist radio station WBAI-FM from a Lower Manhattan studio during a weekly show called “Radio Unnameable.”

Bob Fass is the host of the show, which airs at midnight. In the 1960s, Mr. Fass helped create the format known as free-form radio, in which D.J.’s control the programming, and he is known for the long, discursive and often meditative conversations he carries on with his unseen listeners — insomniacs, lobster-shift workers and night owls across the city.

Starting nearly 20 years ago, Mr. Fass began broadcasting dozens of conversations that he had recorded when Mr. Davis called from a prison pay phone. During those exchanges, Mr. Davis often revisited and interpreted the trials at which he was convicted — of weapons possession and the murder of a drug dealer.

He also described the drudgery of incarceration.

On Saturday, Mr. Fass dug a master tape of a 1990 show from his archives and played it for this reporter. During that show, Mr. Davis had called in from Rikers Island. Asked how he was doing, he replied, “Trying to keep my head above water.” He described a deep sense of fear that pervaded prison life and then gave his views of such figures as Manuel Noriega, George H. W. Bush and Nelson Mandela.

The unusual talks began after a conversation between Mr. Fass and the civil rights lawyer William Kunstler. Mr. Kunstler represented Mr. Davis, a black fugitive from the Bronx, at his racially charged trial in 1988, where he was charged with firing a gun at nine white police officers during a shootout, striking six.

Jurors, believing his lawyers’ assertions that he had acted in self-defense, acquitted Mr. Davis of attempted murder, convicting him only of weapons possession. The verdict of not guilty on the more serious charge was cheered by supporters, who saw him as a folk hero, but denounced by police officers, prosecutors and the mayor.

Mr. Kunstler suggested that the most reviled criminals need the best lawyers, Mr. Fass recalled. The host decided that because Mr. Davis was the continuing subject of such impassioned feelings, he deserved to be heard.

“I was really impressed by his creativity and his mind,” Mr. Fass said in a phone interview on Thursday before going on the air. “Justice is not just for people who are not guilty.”

Not everyone agrees with that analysis.

Paul Gentile, the Bronx district attorney at the time, said that while Mr. Davis had the right to be heard, it would be a mistake to view him as a crusader for justice.

The last contact between the convict and the radio host came on Monday night, when Mr. Davis called Mr. Fass, eager to arrange another taping session. They agreed on Wednesday night at 9.

As Mr. Fass was preparing for a call from the Shawangunk Correctional Facility in Ulster County, he heard from a relative of Mr. Davis’s that Mr. Davis, 41, had been killed in a prison yard.

So, when Mr. Fass took over the WBAI microphone Thursday night, he found himself broadcasting words about Mr. Davis rather than words from him. Lynne F. Stewart, who had represented Mr. Davis along with Mr. Kunstler, called in to the studio. So did others, many of whom had never met Mr. Davis but who still had opinions about him.

“I’m still a little shaken,” Mr. Fass said in the interview. “He said he had a lot to tell me.”]